From: Austin Clements <aclements@csail.mit.edu>
To: Mark Walters <markwalters1009@gmail.com>, notmuch@notmuchmail.org
Subject: Re: [PATCH] emacs: jump: fix compile warning on emacs 23
In-Reply-To: <1409824014-14622-1-git-send-email-markwalters1009@gmail.com>
References: <1409824014-14622-1-git-send-email-markwalters1009@gmail.com>
User-Agent: Notmuch/0.18.1+86~gef5e66a (http://notmuchmail.org) Emacs/24.3.1
	(x86_64-pc-linux-gnu)
Date: Mon, 22 Sep 2014 18:57:07 +0000
Message-ID: <87fvfj1o1o.fsf@csail.mit.edu>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: list

LGTM.  I'm a little surprised this is necessary, but whatever.

I think the eval-and-compile has to be top-level; it's certainly not
wrong for it to be top-level.  (I like the comment in the
eval-and-compile implementation: ";; Remember, it's magic.")

On Thu, 04 Sep 2014, Mark Walters <markwalters1009@gmail.com> wrote:
> notmuch-jump uses window-body-width which is not defined in emacs
> 23. To get around this it does
>
> (unless (fboundp 'window-body-width)
>   ;; Compatibility for Emacs pre-24
>   (defalias 'window-body-width 'window-width))
>
> This makes sure window-body-width is defined and all should be
> well. But it seems that the byte compiler does not realise that this
> guarantees that window-body-width will be defined and so, when
> compiling with emacs 23, it gives an error
>
> In end of data:
> notmuch-jump.el:172:1:Warning: the function `window-body-width' is not known to be defined.
>
> Domo and I came to following on irc: wrap the (unless (fboundp ...))
> inside eval-and-compile which ensures that both the test and the
> defalias (if needed) happen at both compile and load time.  This fixes
> the warning.
> ---
> I think Domo and I were both not completely sure whether the
> eval-and-compile should be inside or outside the (unless fboundp ..)
> or not (ie should it wrap the unless fboundp or just the defalias) nor
> whether it should be eval-and-compile or eval-when-compile.
>
> We think this is the right version but it would be good to have confirmation.
>
> I tested notmuch jump inside emacs 23 and 24 with notmuch-emacs
> compiled with emacs 23 or 24 (ie all four combinations) and it seemed to work.
>
> Best wishes
>
> Mark
>
>
>
>  emacs/notmuch-jump.el |    7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/emacs/notmuch-jump.el b/emacs/notmuch-jump.el
> index 5eb0949..2706b6c 100644
> --- a/emacs/notmuch-jump.el
> +++ b/emacs/notmuch-jump.el
> @@ -25,9 +25,10 @@
>  (require 'notmuch-lib)
>  (require 'notmuch-hello)
>  
> -(unless (fboundp 'window-body-width)
> -  ;; Compatibility for Emacs pre-24
> -  (defalias 'window-body-width 'window-width))
> +(eval-and-compile
> +  (unless (fboundp 'window-body-width)
> +    ;; Compatibility for Emacs pre-24
> +    (defalias 'window-body-width 'window-width)))
>  
>  ;;;###autoload
>  (defun notmuch-jump-search ()
> -- 
> 1.7.10.4
>
> _______________________________________________
> notmuch mailing list
> notmuch@notmuchmail.org
> http://notmuchmail.org/mailman/listinfo/notmuch